Internal combustion engines generate exhaust as a by-product of fuel combustion within the engines. Engine exhaust contains, among other things, unburnt fuel, particulate matter such as soot, and harmful gases such as carbon monoxide or nitrous oxide. To comply with regulatory emissions control requirements, engine exhaust must be cleaned before it is discharged into the atmosphere.
Engines typically include after-treatment devices that remove or reduce harmful gases and particulate matter in the exhaust. The after-treatment devices may be located in an after-treatment system mounted either on the engine or on a frame of a machine associated with the engine. An on-engine after-treatment system must meet a large number of criteria designed to ensure longevity and ease of use. For example, an on-engine after-treatment system should be capable of being assembled in a relatively limited amount of space. Moreover, the components used for mounting the after-treatment system must be able to carry the weight of the after-treatment system and withstand loads generated because of sudden changes in velocity or temperature, while maintaining general alignment of an exhaust inlet of the after-treatment system with an exhaust outlet from the engine.
An exemplary after-treatment system is disclosed in World Intellectual Property Organization International Publication No. WO 2011/087819 of Kiran et al. that was published on Jul. 21, 2011 (“the '819 publication”). Specifically, the '819 publication discloses a mounting system for an exhaust after-treatment system that is isolated from shock and vibration loads. The disclosed system includes isolators that attach the exhaust after-treatment system to a support structure. The '819 publication discloses two different types of isolators, namely stiff isolators and soft isolators. The stiff isolators are used at one end of the mounting system to limit movement of the after-treatment system at that end. The soft isolators are used in other locations to allow for thermal expansion.
Although the system of the '819 publication may be adequate for some situations, it may also be problematic. In particular, the stiff isolators may not sufficiently constrain movement of the exhaust inlet of the after-treatment system during operation of the machine. As a result, the exhaust inlet of the after-treatment system and the exhaust outlet of the engine may become misaligned or may induce stresses on the coupling between them. Further, the soft isolators may limit an amount of thermal expansion of the after-treatment system, thereby inducing stress in the after-treatment devices. The '819 publication also does not disclose a way to prevent the after-treatment system from moving sideways (orthogonal to a longitudinal axis of the after-treatment system) during operation of the machine.
The mounting system of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.